It was the 33-year-old's second Olympic medal having taken silver back in 2008 at Beijing.

His donation enabled compatriot Olek Szymanski, who has retinoblastoma (an eye cancer affecting young children), to fly to New York to undergo treatment.

"My silver medal is worth a lot more than a week ago," said Malachowski.

"It is worth the health of little Olek."

He added: "We were able to show that together we can do wonders. It is our great shared success.

He added: "We were able to show that together we can do wonders. It is our great shared success.

"Winning an Olympic medal is one of an athlete's life dreams. Of course, the most precious is gold.

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Most memorable moments from Rio 2016

"I did everything in my power to get it. Unfortunately this time I did not succeed."

Malachowski made his original appeal via Facebook where he remarked: "In Rio I fought for the gold. Today I appeal to everyone ― let's fight together about something that is even more precious: the health of this fantastic boy.